At present, despite decades of research, there is no cure for HIV. So anyone who claims to be able to do so is lying. And that includes a case that has recently come to light in the U.K., where a man has been selling olive oil as a miracle cure for HIV. And cancer, of course.

Reported by The Sun, 63-year-old Gilbert Deya, a self-proclaimed Archbishop, has been giving dangerous false hope to those with life-threatening conditions by selling them “personally anointed” bottles of branded extra virgin olive oil. Alongside more than doubling the price of the cooking ingredient, he offers a leaflet describing how the oil will help with everything from debt to disease.

During an undercover investigation, the newspaper recorded Deya saying: “Don’t use any oil except this oil… and the cancer will just disappear. The healing will take place.”

This isn’t actually the first time such a situation has been reported in the U.K. A few years back, a church called the Victorious Pentecostal Assembly was caught selling bottles of olive oil mixed with blackcurrant juice as a cure-all, but it seems that there is a common theme emerging as once again, HIV and cancer were included in the list of ailments supposedly banished by the concoction.

Rumors that HIV can be cured by olive oil actually go way back to the early days of the epidemic. It’s unclear as to why olive oil seems to be at the center of so many fraudulent medical claims, but this could be due to the range of health benefits that have been attributed to the product. Olive oil, key to the famous “Mediterranean diet,” is rich in “healthy” fats called monounsaturated fatty acids, which have been shown to be beneficial for cholesterol levels and blood sugar. In addition, olive oil contains high levels of the antioxidant oleocanthal, which lab studies have shown can exert anticancer activities on cells in a dish.

But there are lots of ingredients in healthy foods, particularly fruit and veg, that have desirable properties and even appear to target cancer cells or viruses in lab studies. That does not mean that simply eating them is sufficient to reap such beneficial effects – most studies use concentrations that realistically couldn’t be obtainable by diet alone.

While unfortunately there is still no one-size-fits-all treatment that will work on every cancer, nor a cure for HIV, effective treatments for both do exist, and there is no good evidence that alternative therapies work.